Air-stable, unoxidized, hydrocarbon-dispersible boron nanoparticles

Abstract

Here we describe a simple method to produce boron nanoparticles with control over surface chemistry and dispersiblity in different solvents, with potential applications ranging from high energy density fuels to neutron capture therapy. The methodology should be adaptable to many hard materials; indeed, we have produced hydrocarbon-dispersible silicon nanoparticles using a procedure similar to that described below. The method, based on high-energy milling, with subsequent sedimentation to separate aggregates, produces gram quantities of nanoparticles in a narrow distribution of particle sizes centered around 50 nm, and should be readily scalable to industrial scale production.

Binding of Alkenes and Ionic Liquids to B–H-Functionalized Boron Nanoparticles: Creation of Particles with Controlled Dispersibility and Minimal Surface Oxidation

“…It should be noted that this approach is complementary to the use of IL propellants where boron is incorporated into the IL constituents directly, as recently reviewed by Zhang and Shreeve. 16 This work follows on earlier studies that demonstrated efficient production of boron nanoparticles in the 50−150 nm size range by ball milling, with simultaneous capping by ligands including oleic acid 17,18 and several hypergolic ionic liquids (ILs), including 1-methyl-4-amino-1,2,4-triazolium dicyanamide ([MAT][DCA]) and 1-butyl-3-methylimidizolium dicyanamide ([BMIM][DCA]). 19,20 In each case, the particles were air-stable with minimal oxidation, and highly dispersible in hydrocarbons (oleic acid-capped) or ILs propellants (ILcapped).…”

Modeling the stability and growth of metalloid clusters for energetic materials

“…[5] There has been considerable recent interest in developing metal/organic structures that address these issues and might allow for systems with fast reaction kinetics that still retain some of the high energy density of pure metals. [6,7,8,9,10,11,12] At the micron and nanoparticle scales, organic layers are being pursued as an alternative passivation to the native oxide layer, [6,9] or as a means of assembling metal particles into structured energetic materials. In recent work we have considered low-valence metalloid clusters as materials that may allow metal oxidation on even faster timescales than coated nanoparticles.…”

Sonochemical synthesis of reactive boron nanomaterials and their combustion properties

“…However, the combustion of B in reactive formulations has all kinds of problems that result from the low melting B 2 O 3 protecting the surfaces from further oxidation, the high melting and boiling points of boron, and HOBO formation in systems that contain hydrogen. A solution to the problem of incomplete combustion can be found in making the fuel nanoscale [2][3][4][5]. This is an account of our efforts to synthesize and combust nanoboron materials.…”